1. Field of the Invention
The present invention relates generally to air conditioning systems for motor vehicles and, more specifically, to a condenser with an integral receiver dryer for an air conditioning system in a motor vehicle.
2. Description of the Related Art
It is known to provide a condenser for an air conditioning system in a motor vehicle. The condenser typically receives a fluid such as a refrigerant in a vapor phase, at a reasonably high temperature, and cools the vapor phase to transform it to a liquid phase. The condenser normally includes a plurality of tubes extending between opposite headers. The condenser also includes a plurality of cooling fins disposed between the tubes. One type of condenser, often referred to as a multi-pass condenser, includes a plurality of baffles placed in one or both of the headers to direct the refrigerant through a plurality of flow paths. As the refrigerant flows in a back and forth pattern through the condenser, heat is transferred from the vapor phase of the refrigerant to condense to the liquid phase. The liquid phase continues to flow through the tubes of the condenser until it reaches an outlet where it is drawn off and used in the air conditioning system. When both liquid and vapor phases are present, continued flow of the liquid phase through the tubes decreases the overall efficiency of the condenser as the vapor phase is hindered from contacting and transferring heat to the tubes. Further, the liquid phase of the refrigerant occupies space within the tubes, thus reducing available interior surface area for heat transfer.
It is also known to provide a separate receiver dryer for storage of excess refrigerant from the condenser and to remove any moisture from the refrigerant in the air conditioning system. An example of a separate receiver dryer for a condenser in an air conditioning system is disclosed in U.S. Pat. No. 5,755,113. In this patent, a separate receiver dryer fluidly communicates with a condenser. The receiver dryer includes a fluid inlet for receiving a two-phase refrigerant mixture from the condenser and two outlets, both of which direct refrigerant back to the condenser after phase separation. The receiver dryer also includes a quantity of desiccant material to remove moisture from the two-phase refrigerant mixture.
Other examples of receiver dryers used with condensers are disclosed in U.S. Pat. Nos. 5,537,839, 5,546,761 and 5,666,791. However, these receiver dryers utilize separate containers, which are attached to the header or manifold of the condenser by various means. In some cases, the attached containers do not contain the desiccant material. Since the receiver dryer is a separate part, it requires additional space, fittings and brackets to attach it to the air conditioning system.
Although the above receiver dryers have worked well, it is desirable to incorporate a receiver dryer into a condenser. It is also desirable to incorporate a receiver dryer into a manifold of a condenser. It is further desirable to provide a condenser with a receiver dryer having fewer parts and compact installation.